The addition of the highly selective, once-daily dipeptidyl peptidase (DPP)-4 inhibitor sitagliptin (Januvia), compared with glimepiride (Amaryl), to background metformin therapy provides similar glycemic control in type 2 diabetics but, importantly, produces significantly fewer hypoglycemic episodes and also results in weight loss, new data show.

The findings were announced at the 46th European Association for the Study of Diabetes (EASD) meeting.

Most therapeutic guidelines recommend the use of metformin as initial monotherapy for the treatment of type 2 diabetes, Barry Goldstein, MD, with Merck Laboratories in Rahway, New Jersey, explained in his presentation. However, metformin alone is often unsuccessful at achieving adequate glycemic control in type 2 patients, thus necessitating the addition of a second oral antihyperglycemic agent.

Sulphonylureas are the most common oral antihyperglycemic agents used in combination with metformin among patients who do not achieve or maintain glycemic control on metformin alone, he added.

A prior study had shown that the hemoglobin (Hb)A1C-lowering efficacy of adding sitagliptin to ongoing metformin therapy was non-inferior to the addition of the sulphonylurea glipizide.

The present study included 1,035 type 2 diabetic patients who had inadequate glycemic control while on a stable dose of metformin following a two-week placebo-run-in phase.

Patients were randomized to the addition of 30 weeks-treatment with sitagliptin 100 mg/day or glimepiride 1 mg/day (uptitrated to a potential maximum 6 mg/day) to ongoing metformin monotherapy.

The primary efficacy analysis evaluated whether sitagliptin was non-inferior to glimepiride in reducing HbA1C from baseline at week 30 in the per-protocol study population.

The study found overall mean reductions in HbA1C of 0.47% with sitagliptin relative to 0.54% with glimepiride.

Also, 22% of glimepiride-treated patients experienced hypoglycemia compared with 7% of sitagliptin-treated patients.

Sitagliptin treatment was associated with a mean weight loss of 0.8 kg while glimepiride led to a mean weight gain of 1.2 kg.

Managing the risks of hypoglycemia and weight gain are important considerations when physicians choose a medication for their patients so it is important to have data from different treatment regimens, Dr. Goldstein said.

The study was funded by Merck, Sharp & Dohme.

Written by Jill Stein
Jill Stein is a Paris-based freelance medical writer.